Unraveling genes

Looking at a single corn plant, who would expect it to be as genetically complex as a human being? Even more remarkable, who would guess that the majority of genetic material found in a corn plant is the same as that found in a human being or even E. coli bacteria?

Recent leaps in technology have allowed biologists to peel away the mysteries of genetics and discover essential details about plant and animal growth. Biologists now have the tools to identify complete genetic codes. This ability holds the promise to affect virtually every person on earth, especially farmers.

New genetic discoveries will help seed companies quickly pinpoint valuable plant traits to reproduce in seed lines. Farmers will be able to buy seed customized for their own needs based on factors such as soil type, weather predictions, insect pressure and the final destination for the crop.

The first commercial products from these new technologies should arrive within five years, according to Pioneer Hi-Bred International.

"Some of the first commercial products will be improved quality traits like better oil, protein and carbohydrates," says Susan Martino-Catt, Pioneer molecular biologist. "We think further out in five to 10 years, we will see products addressing complex quantitative traits like drought tolerance and brittle snap."

Finding the notes The emerging science of genomics has swept the genetics industry. A word seldom heard two years ago, "genomics" means to decipher a plant or animal's genome or genetic code. Every cell in a plant or animal contains a complete genome, unique to itself. This is why only one cell from a hair strand or drop of body fluid is needed to identify a person in today's sophisticated forensics labs.

Amazingly, a big share of our genetic code is similar to the codes of other living things. Geneticists explain that the components of a code are much like piano keys. All music comes from one range of notes. But the timing and the order in which the notes are played create an unlimited number and variety of melodies. The same holds true for a genetic code. The position and sequence of genes and the time they are switched on make us human beings versus corn.

"Genomics" became a household word last spring when geneticists announced that a rough draft of the human genome was near completion. For the first time, scientists identified nearly every gene in a human genome and placed them in correct sequence. This discovery made big headlines.

At the same time, massive work proceeds on many plant genomes, including those for rice, corn and soybeans. Decoding these crops began in earnest just five years ago, compared with a decade ago for the human genome. As a result, plant genome work lags behind research on the human gene. But plant biologists are gaining ground, due to new techniques developed through human genetics.

Rice genome complete Recently, rice became the first commercial grain crop to be decoded. In April, Monsanto announced it had completed a draft of the rice genome through collaboration with the University of Washington in Seattle.

Although Monsanto does not sell rice products, the company has a keen interest in the genome because it serves as a model for other crops, including corn. Rice's genetic code is much simpler than corn's code, yet its gene sequences tend to be in the same positions as those of corn and other grains.

Monsanto opened its rice genome work to the public on the condition that researchers who patent inventions from Monsanto's data must give the company a chance to negotiate a nonexclusive license.

Corn next? The next big question is, when will the corn genome be decoded? Monsanto researchers are working on the maize genome. But the company declined comment because the Securities Exchange Commission has ordered a news blackout until an initial public offering is complete.

Meanwhile, researchers at Pioneer Hi-Bred report they are near completion of a rough draft of the corn genome.

"No one really knows how many genes there are in corn, but our best guess is 60,000 to 80,000 genes, about the same as the human genome," reports Martino-Catt. "We can say with confidence that we have tags to 80% of all the expressed genes in corn."

Pioneer was the first ag biotech company to enter plant genomics on a large scale back in 1996. Today, the company incorporates genomics work throughout all its research programs, which total $200 million a year.

Phenomenal leap Although it is not as dramatic as the race to decode the human genome, Martino-Catt says the seed industry's search for the corn genome is like a "thirst for knowledge." Biologists see decoding an entire genome as a dream come true.

Ten years ago when Martino-Catt completed her doctoral degree, one lab usually would discover just one gene a year. Martino-Catt expected to spend the rest of her life cloning one gene and learning all about it.

In vast contrast, labs at Pioneer now crank out several thousand gene clones overnight. She and many other researchers spend the day sitting at computers and querying the 60,000-gene database. In fact, the latest name for this career is "computational biology" to reflect the integral role the computer plays in biology these days.

"We can do things today that we just did not have the tools and technology to do five years ago," Martino-Catt adds. "Three or four years ago, there was information on less than 400 genes in maize. Now we know 80% of all the genes. This is a phenomenal leap."

Identifying the entire corn genome greatly increases the company's knowledge and understanding of how genes work.

"Genomics helps us be more efficient plant breeders," she says. "Traditional breeding is a very long process of selecting for traits of interest. Using genomic information and biotechnology, we will be able to identify the specific genes responsible for traits and transfer those with very high accuracy and precision [into elite hybrid lines]. We'll be able to improve the traits we care about and not bring along any potential negative traits."

Future yield traits For the first time, complex genetic traits such as increased yield and drought resistance are within reach of plant breeders. Martino-Catt explains these traits could involve from 10 to 100 or more genes. Genomics and high-speed computers will help biologists unravel these traits. Until now, biologists have had the most success modifying traits controlled by single genes.

As a result, growers should be able to buy greatly improved hybrids with these traits by the end of the decade.

Tied into the genomics research is Pioneer's decades of yield data. Martino-Catt says once they find a genotype with characteristics they like, they can go back and track its pedigrees for 70 years.

Then the new hybrids will enter Pioneer's traditional plant breeding program, going through years of wide-area agronomic and performance testing prior to commercial release.

Genomic partners Pioneer and Monsanto are not alone in genomic research. Ag seed companies with parent company ties to the human pharmaceuticals have some type of genomic research under way. The research may be in collaboration with genomic companies that specialize in untangling genetic coding. These companies offer high-powered computers and unique technology that didn't exist a few years ago.

Martino-Catt says Pioneer has collaborations with genomic companies such as CuraGen of New Haven, CT, and Oxford GlycoSciences, Oxford, England.

Other ag seed companies without the deep pockets for genomic research plan to license the technology as traits become available.

Some universities are investing heavily in genomic research. One of the most extensive corn genomic projects is led by the University of Missouri and includes Clemson University and the University of Georgia. This project seeks to physically map the maize genome. The National Science Foundation (NSF) granted $11 million over five years to fund the project.

Other university research funded in part through NSF looks at pieces of the plant genomic puzzle. Check out all the projects on the NSF Web site at www.nsf.gov/home/bio/.

Results from university projects become public information, which in turn helps advance other genomics research including Pioneer's. Much of the information gets placed on a public Internet site that researchers from all over the world access. A massive database called GenBank contains genomic information on many plants and animals.

When Martino-Catt finds something in the Pioneer research that interests her, she checks GenBank to see what other researchers have reported about it.

"GenBank is the biggest public repository of sequence information," she says. "It is a very exhaustive collection of sequences from many organisms from microbes to plants to humans." The site's URL is ncbi.nlm.nih.gov/Genbank/.

We've only just begun What happens when researchers complete the map of the corn genome? Martino-Catt says the work is just beginning. The first genome maps will be rough, with many holes and questions. Then biologists and geneticists must identify how genetic materials work so the traits may be enhanced or removed.

But as work continues, new discoveries should lead to new lines that offer more value to growers, consumers and end users.

Biotechnology may score big for growers when new transgenic hybrids to resist corn rootworm come to the marketplace.

Pioneer Hi-Bred opened its research fields in July to show the results of the company's new elite corn-rootworm-resistant lines. Although still two to three years away from the marketplace, the transgenic lines look promising. Introduction depends on research results and regulatory approval.

Herb Eichenseer, a Pioneer entomology research manager, dug corn plants to show how the new lines look compared with controls and plants treated with insecticides. All the plants were inoculated with the same number of corn rootworm larvae. The transgenic elite line clearly outperformed the control and was noticeably better than plants treated with insecticides.

The elite line contains a protein active against corn rootworm larvae. The protein was obtained through work with Mycogen Seeds/Dow AgroSciences. Eichenseer explains the protein is from Bt but is not the same one used in lines resistant to European corn borer.

The corn-rootworm-resistant hybrids remain in Pioneer's test and development stage on restricted company plots. Eichenseer says the company expects to file for EPA approval to continue testing them further in the field.

Although Pioneer's lines will not be available for a few years, Monsanto appears closer to releasing a corn-rootworm-resistant hybrid. In fact, some industry experts suggest the lines will be on the market for next year's crop.

Monsanto declined to comment about the corn-rootworm-resistant lines, citing a Securities Exchange Commission requirement to withhold information until an initial public offering is completed.